This invention relates to backpacks and in particular to a new and improved integral frame backpack.
The Ruck sack with shoulder straps but no frame of any type has been used for many years and still is satisfactory for light loads. The backpack with external frame, originally of wood and now of lightweight metal has been highly developed and is an excellent piece of equipment for heavy loads and trail hiking. The external frame permits carrying of all manner of equipment and distributes the load between the shoulders and waist while providing ventilation between the pack and the hiker. The external frame pack is not suitable for climbing because the load center of gravity is spaced backward from the climber. The frameless or wraparound pack is used for climbing, with the load within the pack and the harnessing providing the stiffening. While being light in weight, the frameless pack is not particularly satisfactory for hiking, particularly in hot weather, because of the close contact between the pack and the hiker.
More recently, the internal frame pack has been used in place of the external frame pack because of the reduction in weight. The internal frame pack has some of the structural characteristics of the frameless pack, but it does utilize vertical metal bars in the pack to provide stiffness.
The various packs referred to above suit certain conditions and have problems with other conditions, and it is an object of the present invention to provide a new and improved backpack with an integral frame which will be relatively light in weight, comfortable, with padding and stiffening and ventilation. It is a further object of the invention to provide such a backpack which does not utilize any metal frame members internally or externally, and which inherently contours itself to fit the back when in use.
These and other objects, advantages, features and results will more fully appear in the course of the following description.